This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Walnuts contain high contents of polyunsaturated fatty acids (PUFA), particularly linoleic acid and linolenic acid. They are also rich in substances such as ellagic acid (a polyphenol), antioxidants, vitamin E, fiber, essential fatty acids, flavanoids, and phenolic acids. Polyphenolic compounds are believed to have multiple biological effects. Despite positive benefits found in consumption of the walnuts, it is not known which specific component of the walnut (ie. whole walnut, walnut skin, defatted walnut, or walnut oil) is most beneficial to health. The goals of the study are: to evaluate the acute, postprandial effects and mechanism of action of various walnut components (separated nut skins, de-fatted nut meat, nut oil) vs. whole walnuts on oxidative stress, inflammation and measures of platelet and endothelial function in healthy adults with moderately elevated cholesterol levels. In addition, we will conduct a novel biochemical analysis of walnut components and isolated fractions in order to further characterize the biological effects of the components of walnuts that could account for the synergistic in vivo effects noted with walnut consumption. Thus, we hypothesize that maximum improvements in oxidative stress, inflammatory markers, platelet and endothelial function will be observed following consumption of the whole nut versus isolated walnut components, thereby leading to an increased understanding of health benefits of walnut intake. We propose to conduct a randomized, 4-period, crossover postprandial study with 20 generally healthy men and women 21 to 60 years of age;BMI = 25 to 39 with moderate hypercholesterolemia.